.center{
    width: 800px;
    margin: 0 auto;
}
.oneword{
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  background-image: url('https://png.pngtree.com/background/20210712/original/pngtree-abstract-modern-neon-frame-background-picture-image_1178251.jpg');
  animation: bg 5s linear infinite;
}

@keyframes bg {
   from{
    background-position: 0;
   } 
   to{
    background-position: 100%;
   }
}